T3L8 Meiosis

Question 1

Describe the process of meiosis

Answer 1

DNA is replicated before meiosis

In Meiosis 1 crossing over occurs
Chromosomes line up in the middle - randomly assorted of whether mum or dad’s c is on left or right.

First divide

In Meiosis 2 each chromatid is pulled apart into opposite cells

Result is 4 genetically different gametes

Question 2

What is crossing over

Answer 2

Homologous chromosomes/Non sister chromatids exchange alleles.

Chromatids twist round and break at the chiasmata where the section of alleles from the other chromatid reattaches

This results in a new combination of alleles and increases genetic diversity

Question 3

What is independent assortment

Answer 3

Random alignment of chromosomes along the equator - which is on which side is completely random

When the chromosomes are pulled apart, the DNA that ends up in the daughter cells is completely random which means that the combination of alleles in each gamete is completely different